title: Kinetics of biofilm formation and desiccation survival of Listeria monocytogenes in single and dual species biofilms with Pseudomonas fluorescens, Serratia proteamaculans or Shewanella baltica on food-grade stainless steel surfaces.
abstract: This study investigated the dynamics of static biofilm formation (100% RH, 15 °C, 48-72 h) and desiccation survival (43% RH, 15 °C, 21 days) of Listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, Pseudomonas fluorescens, Serratia proteamaculans and Shewanella baltica, on the surface of food grade stainless steel. The Gram-negative bacteria reduced the maximum biofilm population of L. monocytogenes in dual species biofilms and increased its inactivation during desiccation. However, due to the higher desiccation resistance of Listeria relative to P. fluorescens and S. baltica, the pathogen survived in greater final numbers. In contrast, S. proteamaculans outcompeted the pathogen during the biofilm formation and exhibited similar desiccation survival, causing the N21 days of Serratia to be ca 3 Log10(CFU cm(-2)) greater than that of Listeria in the dual species biofilm. Microscopy revealed biofilm morphologies with variable amounts of exopolymeric substance and the presence of separate microcolonies. Under these simulated food plant conditions, the fate of L. monocytogenes during formation of mixed biofilms and desiccation depended on the implicit characteristics of the co-cultured bacterium.
authors.affiliation: a Food Science Program, Faculty of Engineering, Department of Process Engineering and Applied Science , Dalhousie University , Halifax , Canada.
authors.forename: Hessam Edin
authors.initials: HE
authors.lastname: Daneshvar Alavi
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Truelstrup Hansen
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D057219:Biofouling; D003890:Desiccation; D005511:Food Handling; D007700:Kinetics; D008089:Listeria monocytogenes / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D011551:Pseudomonas fluorescens / Q000502:physiology* / Q000648:ultrastructure; D012705:Serratia / Q000502:physiology* / Q000648:ultrastructure; D020592:Shewanella / Q000502:physiology* / Q000648:ultrastructure; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D013193:Stainless Steel